Shoe sewing machine



April 1943- F. ASHWORTH ET AL 2,316,761

SHOE SEWING- MACHINE Original Filed March 22, 1939 5 Shets-Sheet l April 0, 1943. F. ASHWORTH ETAL ,3

SHOE SEWING MACHINE Original Filed March 22, 1939 5 Sheets-Sheet 2 April 20, 1943. F. ASHWORTH ETAL.

SHOE SEWING MACHIN E 5 Sheets-Sheet 5 Original Filed March 22, 1939 Y April 1943- F. ASHWORTH ET AL 2,316,761

SHOE SEWING MACHINE Original Filed March 22, 1939 5 Sheets-Sheet 4 SHOE- SEWING MACHINE 5 Sh eets-Sheet' 5 Original Filed March 22, 19:59

y l I II III V In unununouuwml avg Patented Apr. 20, 1943 UNITED STATES PATENT OFFICE SHOE SEWING MACHINE Original application March 22, 1939, Serial No. 263,455. Divided and this application July 18, 1940, Serial No. 346,160

21 Claims.

The present invention relates to improvements in feeding mechanisms for lockstitch shoe sewing machines as disclosed in an application by Ashworth and Whitaker, Serial No. 263,455, filed March 22, 1939, on which United States Letters Patent No. 2,271,611 were granted February 3, 1942, and of which application the present application is a division, and more particularly to that type of feeding mechanism in which the work is fed by a clamp comprising a work support and a cooperating presser foot.

Previous lockstitch shoe sewing machines of the clamp feed type have a pivotal mounting for the work support and presser foot, the axis of which pivotal mounting is arranged vertically, at right angles to the work supporting surface of the work support. When arranged in this way, proper design and adjustment of the parts is somewhat difficult due to the presence of the presser foot and shuttle actuating connections and related parts close to the bearings of the pivotal mounting.

The objects of the present invention are to provide a simple and improved construction and arrangement for the feeding mechanism of a lockstitch shoe sewing machine of the clamp feed type, and to so arrange a pivotal mounting for the work support and presser foot of such machine that the bearings for the mounting will not interfere with the adjustment or operation of the stitch forming devices or their actuating connections.

With these and other objects in view, the present invention is embodied in a lockstitch sewing machine in which the work is fed by the work support and presser foot arranged on a pivotal mounting, the axis of which extends at an acute angle to the plane of the work engaging surfaces of the work support so that the bearing surfaces of the pivotal mounting may be located at the same side of said plane opposite ,to the presser foot and shuttle, thus providing more available space for said parts and their actuatin connections and so that a slight movement towards and from the work may be imparted to the work support. In the form of this feature, as hereinafter described, thrust plates are provided on the frame of the machine to stifien the work support as it swings on its pivotal mounting.

A further feature of the invention is to arrange the presser foot actuating connections in such a way that a yielding squeeze will be applied to the work during feed, thus causing the work to be gripped with uniform pressure without danger of injuring the surface of the Work. According to this feature of the invention, the pressure exerted by the presser foot during the squeezing action may be adjusted. Other features of the invention relate to novel and improved mechanisms for locking the presser foot actuating connections so that the squeezing action may be produced uniformly and at high speeds, and to novel and improved mechanisms for causing the presser foot to be raised from the work during back-feeding movement of the presser foot or for causing the presser foot to remain in contact with the work as desired.

Still further features of the invention consist in other devices, combinations and arrangements of parts hereinafter described and claimed, the advantages of which can be readily understood by one skilled in the art from the following description, taken in connection with the accompanying drawings illustrating one embodiment of the invention.

In the drawings, Fig. 1 is a view in elevation and in section, looking from the right-hand side of the sewing head of a machine embodying the present invention; Fig. 2 is a sectional view on an enlarged scale of a portion of the machine, looking from the right side illustrating the presser foot mechanism; Fig. 3 is a plan view, partly in section, of the edge gage and fudge knife adjusting devices of the machine; Fig. 4 is a detail view in side elevation and partly in section of the work feed carriage; Fig. 5 is a sectional plan view of the feed carriage and actuating mechanism therefor; Fig. 6 is a side view of the presser foot and actuating mechanisms therefor; Fig. 7 is a sectional view taken alon the line 1-1 of Fig. 6; and Fig. 8 is a sectional view of the presser foot lock taken along the line 8-43 of Fig. 6.

The machine illustrated in the drawings is of the type disclosed in prior U. S. Letters Patent of Ashworth Nos. 1,169,909 of February 1, 1916, 1824,063 of September 22, 1931, and 2,015,65e of October 1, 1935. The machine is equipped with a curved hooked needle 2, a needle guide 4, a curved awl 6, a shuttle or loop taker 8, a looper H), a thread finger 12, a loop lifter and spreader M, a work support [6, a presser foot !1, and a rotary take-up, all similar, except as hereinafter pointed out, to those of the above patents. To actuate the stitch forming devices. two sewing shafts l8 and 19 are provided. A driving and stopping mechanism is also provided for bringing the machine to rest with the work free to be removed from the machine.

The work is fed in the illustrated machine by the movement of the Work support and presser foot while clamping the work, as in the machine of Patent No. 1,824,063, and the shuttle is similar to that disclosed in Patent No. 2,208,999 of July 23, 1940.

Referring to Figs. 4 and 5, the work support 16 is secured to a feed carriag having a. pivotal mounting, the axis of which extends at an acute angle to the plane of the flat Work engaging surface 20 of the work support. The work support is of U-shape, the work engaging surface 20 of which is at the center of the U between the parallel arms. The arms of the support are clamped to parallel portions of the feed carriage indicated at 22, which carriage is constructed in two parts. The parts of the carriage are secured together and to an inclined pivotal mounting shaft 24 by bolts 26 passing through the parts. The inclination of shaft 24 is such that its lower end extends forwardly towards the front of the machine. To clamp the work support to the carriage 22 and to provide convenient vertical adjustment for the'work supporting surface 20, the parallel arms of the support are perforated to receive clamp screws 28 entering threaded openings in the carriage 22 and the carriage has passing loosely through its parallel portions eccentric headed bolts 30, the heads of which fit within slots formed in the work support. The work support has suitably located holes to provid access to slots in the heads of bolts 30 whereby the bolts may be rotated when the clamp screws 28 ar loosened to raise and lower the work support.

The feed carriage pivot shaft 24 is rotatably mounted at its ends in bearings 32 and 34 (see Fig, 2) on the machine frame, both bearings being below the plane of the work engaging surface 20 of the work support at locations to provide ample space for the other operating mechanisms. The feed carriage 22 is reinforced between its pivotal mounting and the work en: gaging surface of the work support by the formation of hooked portions on the carriage engaging thrust plates 36, thesurfaces of which are at right angles to the pivotal axis of the carriage. The plates 36 are supported in seats formed on a bracket 38 bolted to the machine frame.

The presser foot is secured to theforward end of a presser foot lever 40 fulcrumed'on a'pin 42 supported in lugs extending from the right arm of the feed carriage. The pin 42 has a squared head engaging a slotted guideway in a plate 44 bolted to the bracket 38 to stiffen that portion of the carriage supporting the pin, the hooked portions of the carriage sliding along arcuate edges of the thrust plates 36 and the head of the pin 42 sliding in the slot of the plate 44 during feeding movements of the carriage.

The mechanism for imparting feeding movements to the feed carriage is similar to the mechanism for imparting the feeding movement to the awl in the prior Patent No. 1,169,909 and includes a rearwardly extending arm of the feed carriage pivotally connected to one member of a pair of toggle links and 48 (see Fig. 5), the middle joint of which is connected by a link 50 to one arm of a cam actuated bell crank lever 52. To change'the length of stitch, the toggle link 48 is pivotally mounted on a yoke 54 rotatable in the machine fram on pivots approximately in line with the middle joint between th links 46 and 48. An adjustment of the yoke 54 about its pivots increases or decreases the angle formed by th links of the toggle, thus changing the feeding movements of the feed carriage. To adjust the yoke 54, it is provided with an arm 56 connected by a link 58 to one arm of a bell crank lever 50, the other arm of which is connected by a link 62 pivoted at 64 to a hand operated lever 66 (see Fig. 3).

To compensat for minor irregularities in the parts of the machine, and to adjust properly the osition of the feed carriage without reference to the length of feeding movements, the pivotal connection between the toggle link 48 and the feed carriage comprises a pin 68 (see Fig. 4) passing through a forked end of the link 46 and an eccentric sleeve 10 adjustably clamped in the arm of the feed carriage between the forks of the link. To rotate the eccentric sleeve in the arm of the feed carriage, the sleeve is formed with a flange having spanner holes 12 into which a suitable tool may be inserted. Rotation of the sleeve causes relative positions of the feed carriage along the lin of feed to be changed without affecting the length of the feeding movements.

Referring to Figs. 1, and'4 to 8 inclusive, the mechanism for actuating the presser foot to clamp and release the work comprises an arm 14 pivoted on the presser foot fulcrum pin 42 and connected with the presser foot lever '49, a link 16 having universal joints at its ends connecting the arm 14 with a bell crank lever 18 fulcrumed. on a pin fixed in the machine frame, and a link 82 connecting the bell crank lever 18 and the lower end of a floating lever 84. To provide a pivot point at the lower end of the floating lever, the link 82 is forked (see Fig. 7) and embraces the slotted lower portions of the floating lever, a pivot pin 85. passing through the overlapping parts of the link and lever. 'I'o cause the presser foot to b engaged yieldingly with the work, the central part of the pivot'pin 86 within th slot of lever 84 passes through the forward end of a link 88, the rearward end of which is pivoted on a pin 90 mounted in a curved arm of a three-arm lever 92. The lever 92 is rotatably mounted on a fixed'stud 94 and has connected to a downwardly extending arm the rear end of a relatively long horizontal tension spring 95, the forward end of which reaches the front of the machine. Th forward end of the spring 96 is connected to'an arm 9'! of a tension adjusting device (see Fig. 3) accessibl at the front of the machine and readily adjustable during sewing. The spring 96 acts through the parts 7 To adjust the force with which the'presser 7 foot yieldingly engages the work, the arm 91 to which the presser foot spring 96 is connected is pinned to the lower end of a vertical shaft 99 rotatable in the frame of the machine. Also on the shaft 99 there is made fast a worm gear lBl meshing with a Worm I93 on a horizontal shaft H35 provided with a manually operable adjusting wheel I01 at the front of the machine. Rotation of the wheel through the worm I03 and gear IIH causes the arm 91 to be moved forwardly or rearwardly, increasing or decreasing the tension on the presser foot spring 96.

To lock the presser foot mechanism, the floating lever 84 is connected at a point midway between its ends with a locking device similar to that disclosed in the patent to Gouldbourn et al. No. 2,054,078 of September 15, 1936. The construction of the locking device is illustrated in Fig. 8 and includes central and outer wedge members 98 located in a guideway in a block I bolted securely to the frame of the machine. Between the central wedge member and one of the outer wedge members there is a spacing piece I02 and between the central wedge member and the other of the outer wedge members is a series of steel rolls I04. A relatively fixed bar I06 projects into one end of the gap holding the rolls I04 and at the other end of the gap is a presser foot locking finger I00 which, when actuated by mechanism hereinafter described, presses the rolls together, thus urging the looking members against the inner surfaces of the guideway and the outer surfaces of the spacing piece I02. The wedge members 98 are connected to the floating lever 84 by a pin H0 passing loosely through the members and lever so that, when the members are forced against the guideway, the pin III) forms a fulcrum for the floating lever. When the fulcrum H0 is locked against movement by the locking device, oscillation of the floating lever 84 in one direction will cause the presser foot to squeeze the work against the work support, and in the other direction to release the work from the grip of the presser foot and work support. To oscillate the floating lever, the lever is connected at a point near its upper end with a cam actuated lever H2, which acts when the work is released to extend the tension spring 90. The connection between the floating lever and the cam lever II2 is adjustable to cause different degrees of squeezing and releasing movements to be imparted to the presser foot and comprises a link H4, the ends of which carry studs I I6 releasably clamped within slots at the upper end of the lever 84 and the lower end of lever I I2, respectively.

With certain types of work, it is desirable to permit the presser foot to remain continuously in engagement with the work and to provide convenient means for permitting this manner of operation, the presser foot lever 40 and the actuating arm I4 are connected together by means of a clamping screw I I8 (see Fig, 4) passing through an upstanding arm of the presser foot lever and into a threaded opening in a lug on the arm I4. Surrounding the screw IiB within an enlarged bore in the lug of the arm i4 is a coil spring I20 and, when the screw II8 is backed off, the spring I20 presses the presser foot against the work with a light yielding action, the screw connecting the lever and arm only loosely. Such operation is desirable, for instance, in case a grooving knife is employed on the presser foot. When the screw H8 is tightened to clamp the presser foot lever 40 to the actuating arm I4, the presser foot again will lift from the work during each sewing cycle in the usual way, the spring I20 being rendered inoperative and the lever 40 and arm I4 being rigidly connected.

The mechanism for actuating the presser foot locking device includes the locking finger I08, which forms one arm of a lever I22 fulcrumed on a shaft I24 mounted in the block I00, a link I26 pivotally connected to one arm of the lever I22, and a cam actuated lever I28 fulcrumed on a cross shaft I30 in the machine frame for actuating the link I26.

To assist in releasing suctional effects along the gripping surfaces of the locking members 98, spacing piece I02 and the guideway in which they are mounted, when the locking device is unlocked, the gripping surfaces in the illustrated machine are provided with channels I32 forming a number of projecting elements for gripping the cooperating surfaces of the guideway and wedge members. The channels I32 also provide clearance spaces between the gripping surfaces within which foreign material or loose particles scraped from the gripping surfaces may accumulate without interfering with the locking action.

To prevent engagement of the presser foot and work support when no work is presented to the machine, the presser foot lever 40 carries a stop plate I34 adjustably secured thereto by clamp screws L36 passing through slots in the plate I34. The lower surface of the plate I34, when the presser foot is moved yieldingly towards the work support, strikes a forwardly projecting arm of a bracket I38 carrying the needle and awl supporting stud on the machine frame.

As in the prior machines of the clamp feed type, the cam actuated lever II2 imparts a work squeezing and releasing movement to the presser foot in proper timed relation to the feeding movements of the carriage 22, the squeezing movement occurring during feed and the releasing movement occurring during back feed of the carriage. To limit the pressure of the presser foot on the work during its squeezing movement so as to avoid injury to the surface of the work, in the present machine, the lever II2 is connected through a yielding element to a cam follower arm I40 (see Fig. 2). The lever H2 is fulcrumed on a shaft 142 and the arm I40 is provided with a pair of upstanding lugs between which a laterally projecting arm of the lever II2 enters. The laterally projecting arm of the lever II2 is formed. with a recess within which is mounted a spring H24 acting between the bottom of the recess in the arm and the enlarged head of an adjustable set screw Hi6 mounted in one of the lugs on the cam arm I40. When the cam arm I40 is oscillated in a direction to force the presser foot towards the work support and squeeze the work, it acts through the spring 144, but when the cam arm is oscillated in the opposite direction to raise the presser foot from the work, the other lug of the arm engages the lever I I2, rendering the spring I44 inoperative to hold the presser foot against the work.

To unlock and raise the presser foot manually, there is pivotally mounted on, the pin a manually operable handle lever I48 (see Fig. 1) having a rearwardly extending bar I50 secured thereto extending towards a roll 52 carried by an arm of the presser foo-t unlocking lever 122. When the handle lever is pushed rearwarclly, the bar I50 unlocks the presser foot actuating mechanism and a lateral extension of the handle lever I48 engages a roll I54 carried by the presser foot lever 40 to raise the presser foot from the work. One advantage of this construction is that with the screw I I8 loosened to permit the presser foot to remain yieldingly in engagement with the work, it is possible to raise the presser foot by direct action on the presser foot lever rather than requiring an idle movement to take up the looseness between the presser foot lever and actuating arm 14.

The driving and stopping mechanism is similar to that of prior Patent No. 1,169,909 above referred to and that of Ashworth No. 1,233,539 of July 17, 1917, being provided with high and low speed driving mechanisms mounted on the shaft I9.

The connections between the driving and stopping mechanisms and the presser foot actuating mechanism for automatically unlocking and raising the presser foot from the work when the machine comes to rest include a lever I56, best shown in Fig. 6, loosely mounted on the stud 94 and provided with a set screw I58 arranged to engage a horizontal arm of the lever 92, a link I68 pivotally connected at its lower end with the lever I56 and at its upper end with an arm I62 (see Fig. 1) secured to a shaft I64 rotatable at the rear of'the machine frame and a second upstanding arm I 66 on the shaft acted upon by a set screw I68 carried by a lever I18 of the stopping mechanism. To hold the arm I66 against the set screw I88, a coil spring I12 is stretched between the arm I 68 and the machine frame. When the machine is running, the parts are in the position shown in Fig. 6. Before the machine comes to rest, the connections thus described force the set screw I68 against the lever I56, rocking the lever I56 in a direction to raise the set screw I58 against the arm of the lever 92 (Fig. 1). Just before the set screw I58 engages the lever 92, a flat surface on the arm of the lever I56, which carries the set screw I 58, engages a roll I14 on an elbow lever I16 pinned to a shaft I18 rotatable in the machine frame and provided with an arm I88 carrying a set screw I82 which presses the end of link I26 of the presser foot lock actuating mechanism. To permit the link I26 to move while the lock actuating cam lever I28 to which it is connected remains stationary, the rearward end of the link is drilled to receive a spring I83 compressed between a cap screw I84 at the end of the link and a pin I86 passing through slots in the link and forming the pivotal connection between the link and the cam lever I28. Further movement of the lever I56 causes the presser foot to be raised from the work and the elbow lever I16 to be latched in look releasing position by a notched latch arm I88 loosely mounted on the shaft I38 engaging a pawl I98 on the elbow lever. When the machine is started, the driving and stopping mechanism raises the link I60 and brings a pin I92 adjustably clamped in a slot in the link against the notched arm I88 to release the elbow lever I16 before the lever I56 is actuated to move the set screw I58 away from the lever 92, thus permitting the presser foot to clamp the work in starting the machine before the presser foot mechanism is locked. To holdthe elbow lever I16 from following the movements of the lever I56 as the machine is started, the upper arm I88 engages a hooked finger I94 carried by the frame of the machine.

To enable a change to be made in length of feed, the feed control hand lever 66 is fulorumed on a stud screw I96 passing loosely through the central part of an arm I98 arranged to swing with the hand lever about a fixed pivot 208 (see Fig. 3). When the hand lever is actuated, it rotates about the pivot 208 with the arm I98, actuating the link 62 to cause an adjustment of the feed. The free end of the arm I98 slides along a perforated guide block 202 in which are inserted stop pins 204- to limit the movement of the arm I 96. To permit a more accurate ad .iustment in the movement of the arm I96 than that afforded by removing and inserting the pins 284, in the perforations of the block 282, the block 202 is slidably mounted in the machine frame and has its'position controlled by a micrometer thumb screw 286.

The nature and scope of the invention having been indicated, and an embodiment of the invention having been specifically described, what is claimed is:

1. A lockstitch sewing machine having, in combination, stitch forming devices, and means for feeding the work operated upon by thestitch forming devices comprising a presser foot, and a cooperating work support having a pivotal mounting, the axis of which extends at an angle substantially less than to the plane of the work engaging surface on the work support to cause the work support to move slightly towards and from the work during feeding movement. I

2. A lockstitch sewing machine having, in combination, stitch forming devices, and means for feeding the work operated upon by the stitch forming devices comprising a presser foot, and a cooperating work support having a pivotal mounting, the axis of which extends at an angle substantially less than 90 to the plane of the work engaging surface on the work support, with the inclination of the pivotal mounting extending forwardly towards the front of the machine to cause the work support to move slightly to wards and from the work during feeding movements.

3. A lockstitch sewing machine having, in combination, stitch forming devices, and means for feeding the work operated upon by the stitch forming devices comprising a presser foot, a cooperating work support, and a carriage for the Work support having a pivotal mounting, the axis of which extends at an acute angle to the plane of the work engaging surface of the work support, and thrust plates arranged at right angles to the pivotal axis of the work support to engage the carriage between the pivotal axis of the carriage and the work support.

4. A lockstitch sewing machine having, in combination, stitch forming devices, and means for feeding the work operated upon by the stitch forming devices comprising a presser foot, a cooperating Work support, and a carriage for the work support having a pivotal mounting, the axis of which extends at an acute angle to the plane of the work engaging surface of the work support, thrust plates arranged at right angles to the pivotal axis of the work support, and hook members on the carriage engaging the plates between the pivotal axis of the carriage and the work support to reinforce the carriage.

5. A lockstitch sewing machine having, in com bination, stitch forming devices, and means for feeding the work operated upon by the stitch forming devices comprising a work support, and a carriage for the work support having a pivotal mounting, the axis of which extends at an acute angle to the work engaging surface of the work support, a presser foot, a presser foot fulcrum pin on the carriage about which the'presser foot is actuable towards and from the work support, thrust plates engaging the carriage between the pivotal axis of the carriage and the work support,. and a bracket having a guideway for the presser foot fulcrum pin and a seat for the thrust plates.

6. A sewing machine having, in combination, a main sewing shaft, stitch forming devices, a work support, a cooperating presser foot, mechanism for actuating the presser foot to clamp and release the work comprising a lever connected at one point to the presser foot, means operated from the sewing shaft for locking the lever at a second point, a member actuated from the sewing shaft and connected to said lever at a third point for causing the presser foot to squeeze the work against the work support, and a yielding connection between said member and the presser foot to limit the pressure exerted on the work '7. A sewing machine having, in combination, a main sewing shaft, stitch forming devices, and means for feeding the work operated upon by the stitch forming devices including a work support and a cooperating presser foot, mechanism for actuating the presser foot to clamp and release the work comprising a lever connected at one point to the presser foot, means operated from the sewing shaft for locking the lever at a second point, a member actuated from the sewing shaft and connected to said lever at a third point for causing the presser foot to squeeze the work against the work support during feeding movement of the work support and presser foot, and a yielding connection between said member and the presser foot to prevent injury to the work during the feeding movement.

8. A sewing machine having, in combination, stitch forming devices and means for eeding the work operated upon by the stitch forming evices including a work support, a presser foot and a pivotally mounted carriage on which the work support and presser foot oscillate along the line of feed, yielding means for actuating the presser foot to clamp the work, mechanism for exerting a force on the presser foot in a direction to squeeze the work between the presser foot and work support while the work is being fed and to release the work from the presser foot and work support after the work is fed, and a yielding element in said mechanism to limit the pressure exerted on the work during feed.

9. A sewing machine having, in combination, a main sewing shaft, stitch forming and work feeding devices including a work support and a cooperating presser foot, mechanism for actuating the presser foot to clamp and release the work comprising a lever connected at one point to the presser foot, means operated from the sewing shaft for locking the lever at a second point, a member actuated from the sewing shaft and connected to said lever at a third point for causing the presser foot to squeeze the work against the work support, and a spring for causing the presser foot to engage the work with a predetermined pressure when the locking means is unlocked, a yielding connection between said shaft actuated member and the lever arranged to be brought into operation while the presser foot acts to squeeze the work and to be rendered inoperative while the presser foot is being actuated to release the work, and means for adjusting the yielding connection to increase or decrease the squeezing pressure.

10. An outsole shoe sewing machine having, in combination, a sewing shaft, stitch forming devices, a work support, a presser foot, mechanism operated from the sewing shaft for actuating the presser foot to clamp and release the work, and means operated from the sewing shaft for looking and unlocking the presser foot actuating mechanism comprising a locking wedge block and a guideway, the engaging surfaces of which are formed with suction releasing channels.

11. An outsole shoe sewing machine having, in combination, a sewing shaft, stitch forming devices, a work support, a presser foot, mechanism operated from the sewing shaft for actuating the presser foot to clamp and release the work, and means operated from the sewing shaft for locking and unlocking the presser foot actuating mechanism comprising a locking wedge block and a guideway, the engaging surfaces of which are provided with projecting elements for rendering the locking and unlocking action between said surfaces more effective at high speeds.

12. An outsole shoe sewing machine having, in combination, a sewing shaft, stitch forming devices, a work support, a presser foot, mechanism operated from the sewing shaft for actuating the presser foot to clamp and release the work, mechanism operated from the sewing shaft for locking and unlocking the presser foot actuating mechanism, connections for unlocking the presser foot mechanism and raising the presser foot at the end of a seam, and means for latching the connections in unlocking positionsto cause the presser foot to clamp the work before the presser foot mechanism is again locked.

13. A shoe sewing machine having, in combination, a sewing shaft, a work support, a presser foot, 2. presser foot lever, a pivotal mounting for the presser foot lever on the work support, mechanism operated from the sewing shaft including an arm oscillating on said pivotal mounting for actuating the presser foot to clamp and release the work, and adjustable means for connecting said arm with the presser foot lever rigidly to cause the presser foot to be raised from the work when the work is released or loosely tocause the presser foot to remain in contact with the work.

14. A shoe sewing machine having, in combination, a sewing shaft, a work support, a presser foot, a presser foot lever, a pivotal mounting [for the presser foot lever on the work support, mechanism operated from the sewing shaft including an arm oscillating on said pivotal mounting for actuating the presser foot to clamp and release the work, a spring between said arm and the presser foot lever to cause the presser foot to remain in contact with the work when the work is released, and means for clamping the presser foot lever to the arm to render the spring inoperative.

15. A shoe sewing machine having, in combination, a sewing shaft, a work support, a presser foot, a lever to which the presser foot is secured, mechanism including an arm operated from the sewing shaft for actuating the presser foot to clamp and release the work, means operated from the sewing shaft for locking and unlocking the presser foot actuating mechanism, means for loosely connecting the presser foot lever and arm to cause the presser foot to remain in contact with the work when the work is released, and a manually operable handle acting directly on the presser foot lever to raise the presser foot from the work.

16. A shoe sewing machine having, in combination, a sewing shaft, a work support, a presser foot, a lever to which the presser foot is secured, mechanism including an arm operated from the sewing shaft for actuating the presser foot to clamp and release the work, means operated from the sewing shaft for locking and unlocking the presserfoot actuating mechanism, means for loosely connecting the presser foot lever and arm to cause the presser foot to remain in contact with the work when the work is released, and a handle manually operable to actuate said unlocking means and arranged to act directly on the presser foot lever for raising the presser foot from the work.

17. A shoe sewing machine having, in combination, stitch forming and work feeding devices, means for changing the length of feed including a manually operable member, a perforated guiding block slidably mounted in the machine coopcrating with the manually operable member, removable pins at the sides of the manually operable member engaging the perforations in the block to limit the movement of said member, and rotatable screw-threaded means for adjusting the position of the block to change the positions of the pins without removing them from the perforations.

18. A shoe sewing machine having, in combination, stitch forming and work feeding devices, means for changing the length of feed including a manually operable member, a perforated guiding block slidably mounted in the machine coopcrating with the manually operable member, re-

movable pins at the sides of the manually operable member engaging the perforations in the block to limit the movement of said member, and

a thumb screw for sliding the block in a direction to adjust the limiting positions of the pins without removing them from the perforations in the block.

19. An outsole shoe sewing machine having, in combination, a sewing shaft, stitch forming devices, a work support and a presser foot at the front of the machine, and mechanism operated from the sewing shaft for actuating the presser foot to clamp and release the work including a relatively long substantially horizontal tension spring extending from the front towards the rear of the machine, and a tension adjusting device to which the front end of the presser foot spring is connected accessible from the front of the machine and adjustable during sewing operations to change the force of the spring.

20. An outsole shoe sewing machine having, in combination, a sewing shaft, stitch forming de-,

vices, a work support and a presser foot at the front of the machine, and mechanism operated from the sewing shaft for actuating the presser foot to clamp and release the work including a relatively long substantially horizontal tension spring extending from the front towards the rear of the machine, an arm to which the front end'of the spring is connected, a shaft on which the arm is secured, a worm gear on the shaft, a worm meshing with the worm gear, and a manually operable wheel accessible from the front of the machine and adjustable during sewing operations to change the force of the presser foot spring.

21. A lockstitch sewing machine having, in combination, stitch forming devices, means for feeding the work operated upon by the stitch forming devices comprising a presser foot and a cooperating work support having a pivotal mounting, the axis of which extends at an angle substantially less than to the plane of the work engaging surface on the work support to cause the work support to move slightly towards and from the work during feeding movements, mechanism for actuating the presser foot to clamp and release the work'o-perated from the sewing shaft including a presser foot lock, and a member for causing the presser foot to squeeze the work against the work support, and a yielding connection between said member and the presser foot to limit the pressure exerted on the work.

FRED ASHWORTH. CARL F. WHITAKER. 

